Auxiliary blow nozzle for an air jet weaving machine

ABSTRACT

The invention relates to an auxiliary blow nozzle for air jet weaving machines which permits a symmetric division of the warp, said division protecting the structure of the warp threads, when the blow nozzle is immersed in the warp. To this end, an envelope curve (5) which describes the free end (1b) of the nozzle body (1) and which has a radius (R 1 ) runs at an angle (α) relative to the longitudinal axis (4a) of the approximately elliptic cross-section of a nozzle body end area (1a). The surfaces (6, 7) originating from the envelope curve (5) slope downward on both sides to the outer periphery (4) in a manner similar to a roof, and said surfaces (6, 7) thus enclose an angle (β). The respective surface (6, 7) having a radius (R 2 ) graduates into the outer periphery (4). A radius (R 3 ) connects radius (R 1 ) of the envelope curve (5) to the outer periphery (4), and each surface (6, 7) constructs an arc-shaped surface section (6a, 7a) which slopes downward at an angle (γ) relative to the outer periphery (4). The graduations of said surface sections into the adjacent surfaces (6, 7) and into the outer periphery (4) are rounded.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an auxiliary blow nozzle for an air jet weavingloom. Such auxiliary nozzles have an air flow channel with an entranceopening and a nozzle end section with an exit opening.

2. Description of the Related Art Including Information Disclosed in anInformation Disclosure Statement

U.S. Pat. 4,987,930 discloses an auxiliary blow nozzle wherein the exitopening in the nozzle end section has a longitudinal central axis angledrelative to a longitudinal central axis of the air flow channel. Theknown nozzle further includes a longitudinal section extending from saidnozzle end section toward said entrance opening, said longitudinalsection having an approximately elliptically formed outer circumference,an envelope curve reaching partially around said longitudinal centralaxis of said exit opening. The envelope curve defines the free end ofsaid nozzle end section. The envelope curve has a radius R₁, whereby theenvelope curve is rounded toward neighboring surfaces.

Auxiliary blow nozzles having the above known features, are used in airnozzle weaving looms. The longitudinal axis of the exit opening for theair stream extends rectangularly to the extension of the envelope curveof the free end of the auxiliary blow nozzle or rectangularly to thelongitudinal central axis of the approximately elliptical outercircumference of the nozzle body. Such a construction requires for theuse of the auxiliary blow nozzle in practice that for an optimaleffectiveness of the air stream on the weft thread to be inserted intothe weft insertion channel of a reed, the longitudinal central axis ofthe exit opening is tilted at an angle of a few angular degrees in thehorizontal plane relative to the warp threads of a weaving warp, or isdirected at a few angular degrees toward the weft insertion channel ofthe reed. However, such an alignment has the disadvantage that duringthe immersion of the auxiliary blow nozzles into the lower shed of aweaving warp, not all concerned warp threads, which are touched or evenbriefly lifted by the free end of the nozzle, slide off symmetricallyfrom this free nozzle end. Such an alignment further means that therepeated immersion of the auxiliary blow nozzles, which is a technicalcondition of weaving, into the lower warp, leads to damaging of therespective warp threads, when the longitudinal axis of the approximatelyelliptical outer circumference is not aligned in parallel to the courseof the warp threads. These damages are noticeable in the produced fabricand eventually appear as weaving faults in the fabric.

Auxiliary blow nozzles are further known from European PatentPublication EP 0,145,824, which also have a structural assembly asdescribed above. The known nozzle has a structurally fixed, longitudinalcentral axis of its exit opening which is angled relative to the courseof the envelope curve, which forms the free end of the nozzle body, orrelative to the longitudinal axis of the approximately ellipticalcross-section of the nozzle body. The elliptical cross-section iscongruent to the envelope curve. Such a known construction aims atachieving the following:

(a) an optimal effectiveness of the air stream on the weft thread, and

(b) an optimal adaptation of the outer contour of the nozzle body endsection to the course of the warp threads.

However, such a known construction still has a disadvantage in that thelongitudinal central axis of the exit opening extends at an angle ofmore than 90° to the longitudinal axis of the elliptical form of thenozzle body end section. That means that it is more difficult to producethe exit opening, compared to an exit opening aligned at a right angleto the longitudinal axis of the elliptical outer circumference.

OBJECT OF THE INVENTION

In view of the above background it is the object of the invention toprovide an auxiliary blow nozzle, particularly for air jet weavinglooms, which makes possible a symmetric, gentle dividing of the weavingwarp when entering into the lower weaving warp shed.

SUMMARY OF THE INVENTION

The nozzle of the invention is characterized by the following features.According to the invention there is provided an auxiliary blow nozzlefor an air jet weaving loom, comprising an air flow channel having alongitudinal central channel axis and an entrance opening at one end ofsaid channel for connection to a fluid supply, a nozzle end portion atthe other end of said air flow channel, an exit opening in said nozzleend portion, said exit opening having a central opening axis angledrelative to said longitudinal central channel axis, said nozzle furtherincluding a longitudinal nozzle section extending from said nozzle endportion toward said entrance opening, said longitudinal section havingan outer circumferential wall with an oval cross-section, said nozzleend portion comprising a free end wall having an envelope curve reachingpartially around said central opening axis of said exit opening, saidenvelope curve having a first radius, said free end wall including wallportions merging with a rounding into said envelope curve, wherein saidenvelope curve extends at a first angle (α) to a major axis of said ovalcross-section of said outer circumferential wall, wherein said wallportions extending from said envelope curve slope downwardly on bothsides as a roof toward said outer circumferential wall, whereby saidwall portions enclose a second angle (β) and merge into said outercircumferential wall with a second radius (R₂), wherein a third radius(R₃) connects said first radius (R₁) of said envelope curve with saidouter circumferential wall, and wherein each wall portion has a bowshaped wall segment which slopes downwardly at a third angle (γ) towardsaid outer circumferential wall, said bow shaped wall segments havingrounded transitions to neighboring surfaces and to said outercircumferential wall.

Due to the construction of the end section of the auxiliary blow nozzleaccording to the invention it is achieved in an advantageous manner thatthe group of warp threads, which is affected by the entrance of theauxiliary blow nozzle into the lower weaving warp, is dividedsymmetrically, without any impairment whatsoever of the structure of therespective warp threads.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be explained with reference to anexample embodiment illustrated in the accompanying drawings, wherein:

FIG. 1 shows a side view of the present auxiliary blow nozzle on a scaleof about 3:1;

FIG. 2 shows the end section of the present auxiliary blow nozzle in thedirection of the arrow A shown in FIG. 1;

FIG. 3 shows a plan view of the present auxiliary blow nozzle in thedirection of the arrow III in FIG. 2; and

FIG. 4 shows the end section of the present auxiliary blow nozzle in thedirection of the arrow B shown in FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

According to FIG. 1 the present auxiliary blow nozzle 1 comprises atubular body 2 having a first longitudinal section 3 with, for example,a circular cross-section, an air entrance opening 2a, and a secondlongitudinal section 3a having an approximately elliptical or ovalcross-section. An exit opening 2b is worked into the wall of theelliptical cross-section of an end portion 1a of the second longitudinalsection 3a.

The features of the auxiliary blow nozzle 1 according to the inventionare shown in FIGS. 2 to 4 on an enlarged scale compared to FIG. 1.

FIG. 2 shows the end portion 1a of the auxiliary blow nozzle 1 in thedirection of the arrow A in FIG. 1. The free end 1b of the end portionla is enclosed by an end wall formed as an envelope curve 5 as is knownas such. The envelope curve 5 has a first radius R₁, which is largerthan or equal to 3700 μm (R₁ ≧3700μm).

Relative to the prior art, the following features are essential to theinvention, namely:

that the envelope curve 5 extends at a first angle α≧3° (angulardegrees) relative to the longitudinal axis 4a of the approximatelyelliptical or oval cross-section, see also FIG. 3;

that a third radius R₃, of about 1000 μm connects the first radius R₁ ofthe envelope curve 5 with an outer circumferential wall 4 of the endportion 1a;

that a first surface or wall portion 6 and a second surface or wallportion 7 extending from the envelope curve 5, are formed in the mannerof a roof on both sides, both said roof surfaces enclosing a secondangle β of about 120° (angular degrees) with a second radius R₂ ≧300 μm.Both wall portions 6,7 merge into the outer circumferential wall 4; and

that each surface or wall portion 6, 7 forms a vaulted surface or wallsegment 6a, 7a sloping at a third angle γ≧50° (angular degrees) relativeto the radius r of the outer circumferential wall having an ellipticalor oval cross-section 4, and wherein transition areas between thevaulted surface segments 6a, 7a and said surface portions 6, 7 andtransition areas between said vaulted surface segments 6a, 7a and saidouter circumferential wall 4 are rounded.

In a further embodiment of the invention the surface portions 6, 7 maybe slightly vaulted outwardly or these surface portions 6, 7 may beplane surfaces. The vaulting may thereby have a fourth radius R₄ smallerthan 1000 μm.

A multitude of the present auxiliary blow nozzles is arranged on theread stay of an air jet weaving loom not shown. The reed stay carries areed with a weft insertion channel. The arrangement is such according tothe invention that the envelope curve 5 and the surface or wall portions6 and 7 are positioned exactly in parallel to the warp threads 8 of theweaving warp shed and so that the surface or wall segments 6a and 7aextend almost in parallel to the warp threads 8, whereby thelongitudinal axis 2b' of the exit opening 2b is aligned at the firstangle a α≧3° (angular degrees) to the longitudinal axis of the weftthread insertion channel.

Although the present invention has been described and illustrated indetail, it is clearly understood that the same is by way of illustrationand example only and is not to be taken by way of limitation, the spiritand scope of the present invention being limited only by the term of theappended claims.

An auxiliary blow nozzle for air jet weaving machines shaped to assure asymmetric parting of the warp threads forming the lower warp shed,whereby the structure of the warp threads is protected, when the blownozzle enters into the lower warp shed. To this end, an envelope curve(5) which defines the free end (1b) of the nozzle body (1) has a firstradius (R₁) that runs at a first angle (α) relative to the longitudinalaxis (4a) of a nozzle body end area (1a) having an approximatelyelliptic cross-section. Surfaces (6, 7) originating from the envelopecurve (5) slope downwardly on both sides to the outer circumferentialnozzle wall (4) in a manner similar to a roof, whereby these roofsurfaces (6, 7) enclose a second angle (β). The roof surfaces (6, 7)merge with a second radius (R₂) into the outer circumferential nozzlewall (4). A third radius (R₃) connects the first radius (R₁) of theenvelope curve (5) to the outer circumferential nozzle wall (4). Eachroof surface (6, 7) has an arc-shaped surface portion (6a, 7a) whichslopes downwardly at a third angle (γ) relative to the outercircumferential nozzle wall (4). The transitions of the surface portions(6a, 7a) into the adjacent surfaces (6, 7) and into the circumferentialnozzle wall (4) are rounded.

What is claimed is:
 1. An auxiliary blow nozzle for an air jet weavingloom,comprising an air flow channel (2) having a longitudinal centralchannel axis (2a') and an entrance opening (2a) at one end of saidchannel (2) for connection to a fluid supply, a nozzle end portion (1a)at the other end of said air flow channel (2), an exit opening (2b) insaid nozzle end portion (1a), said exit opening (2b) having a centralopening axis (2b') angled relative to said longitudinal central channelaxis (2a'), said nozzle further including a longitudinal nozzle section(3a) extending from said nozzle end portion (1a) toward said entranceopening (2a), said longitudinal section (3a) having an outercircumferential wall (4) with an oval cross-section, said nozzle endportion (1a) comprising a free end wall having an envelope curve (5)reaching partially around said central opening axis (2b') of said exitopening (2b), said envelope curve (5) having a first radius (R₁), saidfree end wall including wall portions (6, 7) merging with a roundinginto said envelope curve (5), wherein said envelope curve (5) extends ata first angle (α) to a major axis (4a) of said oval cross-section ofsaid outer circumferential wall (4), wherein said wall portions (6, 7)extending from said envelope curve (5) slope downwardly on both sides asa roof toward said outer circumferential wall (4), whereby said wallportions (6, 7) enclose a second angle (β) and merge into said outercircumferential wall (4) with a second radius (R₂), wherein a thirdradius (R₃) connects said first radius (R₁) of said envelope curve (5)with said outer circumferential wall (4), and wherein each wall portion(6, 7) has a bow shaped wall segment (6a, 7a) which slopes downwardly ata third angle (γ) toward said outer circumferential wall (4), said bowshaped wall segments (6a, 7a) having rounded transitions to neighboringsurfaces and to said outer circumferential wall (4).
 2. The auxiliaryblow nozzle of claim 1, wherein said bow shaped wall segments (6a, 7a)are positioned opposite each other.
 3. The auxiliary blow nozzle ofclaim 1, wherein said wall portions (6, 7) have an outwardly vaultedshape.
 4. The auxiliary blow nozzle of claim 1, wherein said wallportions (6, 7) are plane.
 5. The auxiliary blow nozzle of claim 1,wherein said first radius (R₁) is ≧3700 μm, said second radius (R₂) is≧300 μm, and said third radius (R₃) is about 1000 μm.
 6. The auxiliaryblow nozzle of claim 1, wherein said first angle (α) is ≧3°, said secondangle (β) is about 120°, and said third angle (γ) is <60°.
 7. Theauxiliary blow nozzle of claim 3, wherein said outwardly vaulted shapeof said wall portions (6,7) has a fourth radius (R₄) <1000 μm.
 8. Theauxiliary blow nozzle of claim 1, wherein said envelope curve (5) andsaid wall portions (6, 7) are aligned in parallel to warp threads insaid air jet weaving loom, whereby said bow shaped wall segments (6a,7a) extend approximately in parallel to said warp threads of a weavingwarp shed.